CardLayout方法顯示（）不工作在awt

Question

我試圖運行CardLayout，但不知道爲什麼show()CardLayout不起作用。我收到錯誤。

package java_files; 

import java.awt.*; 
import java.awt.event.*; 

//import javax.swing.JButton; 

public class AwtLayoutExample { 
    public static void main(String args[]) 
    { 
     Frame f=new Frame("Card Layout"); 
     f.setSize(400,400); 
     f.setVisible(true); 
     f.addWindowListener(new WindowAdapter(){ 
      public void windowClosing(WindowEvent e){ 
       System.exit(0); 
      } 
     }); 
     CardLayout card=new CardLayout(); 
     f.setLayout(card); 
     Panel panelCont=new Panel(); 
     Panel panelFirst=new Panel(); 
     Panel panelSecond=new Panel(); 
     Button b1=new Button("Switch to 2nd Panel"); 
     Button b2=new Button("Switch to 1st Panel"); 
     panelFirst.add(b1); 

     panelSecond.add(b2); 
     panelFirst.setBackground(Color.CYAN); 
     panelSecond.setBackground(Color.GREEN); 
     panelCont.add(panelFirst,"1"); 
     panelCont.add(panelSecond, "2"); 
     card.show(panelCont, "1");  
     b1.addActionListener(new ActionListener(){ 
     public void actionPerformed(ActionEvent e){ 
     card.show(panelCont, "2"); 
     } 
     }); 
     b2.addActionListener(new ActionListener(){ 
      public void actionPerformed(ActionEvent e){ 
       card.show(panelCont, "2"); 
      } 
     }); 
     f.add(panelCont); 
     f.pack(); 
     f.setVisible(true); 
    } 
} 

我只是得到一個空白框架，當我與這個錯誤一起運行它。

Exception in thread "main" java.lang.IllegalArgumentException: wrong parent for CardLayout 
    at java.awt.CardLayout.checkLayout(Unknown Source) 
    at java.awt.CardLayout.show(Unknown Source) 
    at java_files.AwtLayoutExample.main(AwtLayoutExample.java:33) 

Answer 1

您可以申請CardLayout於面板，然後添加其他面板到這個小組

Panel panelCont=new Panel(new CardLayout()); 
panelCont.add("one", panelOne); 
panelCont.add("two", panelTwo); 
panelCont.add("three", panelThree); 

當節目，你可以這樣做：

((CardLayout) panelCont.getLayout()).show(panelCont, "two");